This application relates to the axial retention of a permanent magnet rotor on a generator shaft.
Electrical generators typically include a main generator winding set mounted on a rotor shaft. The main generator windings rotate in proximity to main stator windings, and generate electricity when the shaft is driven to rotate.
The operation of modern generators is quite complex, and includes controls and safety features. A permanent magnet rotor is also fixed to the rotor shaft, and driven to rotate adjacent to its own stator. The energy generated by the rotation of the permanent magnet rotor is utilized for control or safety functions. The permanent magnet rotor is preferably precisely positioned on the rotor shaft such that it is in a desired location relative to its stator.
Typically, the permanent magnet rotor is interference fit on the rotor shaft. Under some high speed and high vibration applications, such as may be found in an aircraft application, as an example, the permanent magnet rotors have sometimes become loose and misaligned.
To address this, locking tabs and threaded locking nuts have been utilized to hold the permanent magnet rotor on the rotor shaft. However, these systems have not always adequately locked the rotor itself, and further require additional parts, thus increasing the cost and complexity of assembly, as well as increasing the length and weight of the generator.